'ineffectively-separated' originates from the combination of 'ineffectively' and 'separated', where 'ineffectively' means 'not producing the desired effect' and 'separated' means 'divided or kept apart'.

The term 'ineffectively-separated' evolved from the need to describe situations where separation is attempted but not achieved effectively.

Initially, it meant 'not effectively divided', and this meaning has largely remained the same in modern usage.